Introduction to Biomedical Instrumentation

What is Biomedical Instrumentation?

We use the term “bio” to denote something related to life. When basics of physics and chemistry get applied to the living things, and we name them as Biophysics and Biochemistry. So when the discipline of engineering and medicine interacts, it is called Biomedical Engineering. Biomedical engineering is the application of knowledge and technologies to solve the problem of the living system. It involves diagnosis, treatment and prevention of disease in human. As the medical field is emerging, the area of Biomedical Engineering is expanding.

Biomedical Instrumentation

It involves measurement of biological signals like ECG, EMG, or any electrical signals generated in the human body. Biomedical Instrumentation helps physicians to diagnose the problem and provide treatment. To measure biological signals and to design a medical instrument, concepts of electronics and measurement techniques are needed.

Components of Biomedical Instrumentation System

Any medical instrument consists of the following functional basic parts

1. Measurand: The measurand is the physical quantity, and the instrumentation systems measure it. Human body acts as the source for measurand, and it generates bio-signals. Example: body surface or blood pressure in the heart

2. Sensor / Transducer: The transducer converts one form of energy to another form usually electrical energy. For example, the piezoelectric signal which converts mechanical vibrations into the electrical signal.
The transducer produces a usable output depending on the measurand. The sensor is used to sense the signal from the source. It is used to interface the signal with the human.

3. Signal Conditioner: Signal conditioning circuits are used to convert the output from the transducer into an electrical value. The instrument system sends this quantity to the display or recording system. Generally, signal conditioning process includes amplification, filtering, analogue to digital and Digital to analogue conversions. Signal conditioning improves the sensitivity of instruments.

4. Display: It is used to provide a visual representation of the measured parameter or quantity. Example: Chart recorder, Cathode Ray oscilloscope (CRO). Sometimes alarms are used to hear the audio signals. Example: Signals generated in Doppler Ultrasound Scanner used for Fetal Monitoring.

5. Data Storage and Data Transmission: Data storage is used to store the data and can be used for future reference. Recent days Electronic Health records are utilized in hospitals. Data transmission is used in Telemetric systems, where data can be transmitted from one location to another remotely.
Biomedical Instrumentation

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